NASA launches Psyche, a mission to explore a metallic asteroid | ET REALITY


Is asteroid Psyche really just a chunk of mostly metal? Is the object, which is nearly as wide as Massachusetts, the core of a baby planet whose rocky outer layers were stripped away during a cataclysmic collision in the early days of the solar system?

Right now, all astronomers can say is maybe, maybe not.

NASA is launching a spacecraft, also called Psyche, on a journey to the asteroid belt between Mars and Jupiter to find out.

“We’re really going to see some kind of new object, which means a lot of our ideas are going to turn out to be wrong,” said Lindy Elkins-Tanton, a professor of Earth and space exploration at Arizona State University, who serves as the investigator. main mission.

Demonstrating the opposite, he added, “is, I think, the most exciting thing about science.”

That journey in search of answers began Friday at 10:19 a.m. Eastern Time. Falcon Heavy, the largest of SpaceX’s operational rockets, lifted off from the Kennedy Space Center in Florida, sending the massive spacecraft on a journey that will last about six years and cover billions of miles.

Friday’s flight beat early, unfavorable weather forecasts for what appeared to be a flawless takeoff. About eight minutes into the flight, the rocket’s upper stage entered a 45-minute inertia period during which it will prepare to deploy the spacecraft on its flight away from Earth. You can watch the flight in progress in the video player above or on NASA YouTube Channel.

The asteroid called Psyche has long been a curious enigma. Discovered in 1852 by Annibale de Gasparis, an Italian astronomer, it was named after the Greek goddess of the soul, and was only the sixteenth asteroid discovered. In early observations, it was, like the other asteroids, a star-like point of light moving in an orbit around the sun, and not much else.

Beginning in the 1960s, astronomers discovered in telescope observations that Psyche’s color was similar to that of iron meteorites that fell to Earth, said Jim Bell, a professor of Earth and space exploration also at Massachusetts State University. Arizona, who will lead studies of the asteroid with the spacecraft’s camera instrument. Astronomers bounced radar pulses off Psyche, and the reflections returning to Earth were brighter than those coming from other small objects in the asteroid belt.

“It became quite clear that there is some component of the surface that is highly reflective of radar,” Dr. Bell said. “And the easiest way to do it is with metal fragments.”

And then, as scientists watched Psyche pass relatively close to larger worlds, its orbit deviated in a way that suggested something quite massive and potentially much denser than rock.

Most rocks such as granite have a density of two to three grams per cubic centimeter. Water, whether liquid or ice, has approximately one gram per cubic centimeter. Metals like iron are much denser, between six and nine grams per cubic centimeter.

“Some of those early estimates said, wow, this is actually quite unusual,” Dr. Bell said.

Psyche seemed to be almost pure metal. Earth’s core is made of iron and nickel, and Psyche’s measurements suggested it could be the remnant of a similar core that belonged to a baby planet. These worlds are known as planetesimals, where temperatures are high enough for the densest metals to melt and fall to the center.

It’s impossible to explore the core of a planet like Earth 1,800 miles below the surface, but going to Psyche could provide more information about what’s at the center of our planet.

Or that hypothesis could be completely wrong.

“The psyche could be something completely different than that,” Dr. Elkins-Tanton said. “I’d love to be totally surprised.”

More recent measurements have led to lower estimates of the asteroid’s density, just under four grams per cubic centimeter: still denser than rock and ice, but not as dense as metal. That suggests Psyche is made of metal plus something else: maybe rock, maybe empty space.

“My best guess is that it’s more than half metal based on the data we have,” Dr. Elkins-Tanton said.

If Psyche turns out to be full of valuable metals, it is too far away for anyone to extract it using current technologies. Dr. Elkins-Tanton points out that even at its closest point, Psyche is about 150 million miles from Earth, which is about five times farther than Earth is from Mars in the position of both planets. closest possible approach.

The Psyche mission was scheduled to launch a year ago. The spacecraft had already been sent to the Kennedy Space Center. But engineers ran out of time to test all the navigation software before the launch window closed.

Once launched, the Psyche spacecraft will head toward Mars, passing by the red planet in May 2026 and using its gravity as a sling toward the asteroid Psyche, arriving in August 2029 after traveling 2.2 billion miles.

The spacecraft will spend at least 26 months in orbit around the asteroid studying the body with instruments that include a magnetometer to measure magnetic fields, a camera to take photographs of the surface and a gamma-ray spectrometer to identify what the asteroid is made of. . .

Additionally, the spacecraft’s radio will be used to measure the asteroid’s gravity by measuring slight changes in the frequency of the Doppler signal, which increases as it approaches Earth and decreases as it moves away. This could give more information about its composition and internal layout.

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